Furnace for steam-boilers



(No Model.)

J. JOHNSON.

FURNACE FOR STEAM BOILERS. No. 248,864.. Patented Nov. 1,1881.

Fig-1 Witnesses Inventor muwst NITED STATES PATENT OF ICE.

JAMES JOHNSON, OF BAY VIEW, \VISOONSIN.

- FURNACE FOR STEAM-BOILERS.

SPECIFICATION forming part of Letters Patent No. 248,864, dated November1, 1881,

Application filed July 22, 1881.

To all whom it may concern Be it known that I, JAMES JOHNSON, a citizenofthe United States, residing at Bay View, in the county of Milwaukeeand State of WViscousin, have invented certain new and usefulImprovements in Furnaces for Steam-Boilers; and I do hereby declare thefollowing to he a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same, reference being had to the accompanying drawings,and toletters or figures of reference marked thereon, which form a partof this specification.

My invention relates to improvements in furnaces for steam-boilers; andit consists of the peculiar relative arrangements of the fire-box,boiler, fines, and air-passages to each other, whereby a more perfectcombustion of the fuel and gases is attained and a higher temperaturewith the less quantity of fuel is produced.

My invention is further explained by the accompanying drawings, inwhich- Fignre 1 represents a transverse section of the furnaces on aline immediately in front of the boiler. Fig. 2 is a longitudinalsection. Fig. 3 is a ground plan.

Like parts are represented by the same reference-letters throughout theseveral views.

A is the fire-box.

I) is the grate.

(l is a combustion-chamber, through which the flame passes from thefire-box to the boiler. d d d d are cold-air passages, through which theexterior air enters the combustion-chambers and min gles with the blazeand gases that have escaped from the fire-box, and thus supplies therequired oxygen to produce a more perfect (No model.)

combustion, whereby nearly, if not all, the smoke and gases are consumedwithin the furnace, thus greatly increasing the heat and reducing thequantity of fuel which would otherwise be required.

fffffare flues communicating from the combustion-chain her to theboiler. The object of the several passages f is to subdivide the flameand distribute it more uniformly beneath theboiler. 'IhechamherOiscurved outwardly, as shown, to permit the flame to spread as it passesto the boiler.

g is a passage through which the heat and flame pass beneath the boilerto its rear end, when their courseis turned forward through the fines hin the boiler to its front end, when they pass upward in the smoke-stackl, the course of the draft through the furnace beingindicated by thearrows.

Having thus described my invention, what 1 claim as new, and desire tosecure by Letters Patent, is-

In furnaces for steam-boilers, the combination of the fuel-box, asemicircular combustionchamber, 0, boiler it, said com bustion-chamberbeing arranged between said fuel-box and boiler, cold-air passages d d,arranged upon the respective sides of the combustion-chamber andcommunicating with the interior air-fines f, andpassage g, allsubstantially as and for the purpose specified.

In testimony whereof I affix my signature in presence of two witnesses.

JAMES JOHNSON.

Witnesses:

JAS. B. ERWIN, J. PETER WEcusELBuRG.

